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layzee_me84
Apprentece
Malaysia
5 Posts |
 Posted - Dec 10 2006 : 1:16:49 PM
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Hello, my name is elda and im a student. i have to make an automatic switch on system for car headlamps. The function of these system is to turn on the headlamps according to ambient lights and when the car is in motion. I used the Automatic Headlight Brightness Switch circuit as the light sensor so that it can turn on the lights when the light level is low. But of course, i have to modified the circuit so it works as i want it to be. I have attached the circuit url below. The problems is, i dont know how to detect when the car is in motion and the circuit that should i use to make it as a switch to turn on the headlamps....Im really worried...Help me plsss....
This is my circuit pic url http://www.geocities.com/layzee_me84/headlightcircuit1.bmp
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Aaron Cake
Administrator
Canada
6718 Posts |
Posted - Dec 11 2006 : 1:16:18 PM
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| Most cars have a vehicle speed sensor which outputs a pulse train whos frequency is based on the speed of the car. You can use a simple timer to determine that the car is moving (ie. the pulse train continually triggers the timer so that the timers output stays on while the car is in motion). |
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layzee_me84
Apprentece
Malaysia
5 Posts |
Posted - Dec 30 2006 : 06:17:29 AM
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| i need to know..i used multisim to run my circuit,and the circuit work but when i assembled the components the circuit didnt work as it should be?what could be wrong? |
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Aaron Cake
Administrator
Canada
6718 Posts |
Posted - Dec 30 2006 : 11:26:19 AM
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| Who knows? Did you make any changes to the circuit? Are the transistors connected properly? |
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layzee_me84
Apprentece
Malaysia
5 Posts |
Posted - Dec 31 2006 : 11:49:36 AM
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| yes it is..i need to know, does relay need individual power supply?cant i connect the relay source with the circuit? i didnt make any changes to the circuit. but before i attached the relay to the circuit i test weather the circuit works or not by checking the current from the circuit, and it works just fine. if there are changes in the ambient light the current also change. but when i attached the relay it just didnt work at all. im new in relay so i think the problems is the relay.. can you tell me which type of relay that i can use for these circuit? i been using srb-12vdc-sl-c relay |
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Aaron Cake
Administrator
Canada
6718 Posts |
Posted - Jan 01 2007 : 12:11:18 PM
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| You can connect the relay to the same power source, but the contacts of the relay should be used to switch your lights and not share power or ground with the circuit. Are you sure you have the coil of the relay connected properly? In most automotive relays, the coil is terminals 85 and 86, if I remember correctly. |
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cyclopsitis
Nobel Prize Winner
Canada
732 Posts |
Posted - Jan 13 2007 : 7:49:34 PM
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The motion control? Does it have to be exactly when the car is moving or could it be with the car is put in to drive or out of park? You could put a pressure switch that is held open when the car is in park but once you shift it into a "gear" (R,N,D,1,2) The switch would no longer be held open and it would close the circuit to turn it on. Just an idea for you.. I don't know if it would be possible in the car your talking about but if that "turns some light bulbs on" (ha-ha no pun intended LOL) then alright!
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automatic headlight circuit-help me pls...
